Data transmission device and reception device in wireless AV system

ABSTRACT

The present invention relates to a data transmission device and reception device in a wireless AV system. Disclosed in the present specification is a wireless data transmission device comprising: a processor for generating a compressed bitstream by encoding media data; and a communication unit for segmenting the compressed bitstream, mapping the segmentation results to MSDUs, generating an MPDU frame sequentially including a MAC header, a frame body, and an FCS associated with the MAC header in order to transmit the MSDUs, generating a PPDU frame sequentially, which includes a preamble to which at least a portion of the MAC header is mapped, at least one PPDU to which the frame body and the FCS are mapped, and a TRN field, and transmitting the PPDU frame through a wireless channel. A data transmission rate can be improved through a reduction in overhead information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/KR2019/006781, filed on Jun. 5, 2019, the contents of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to wireless communication, and more specifically, to an apparatus and method for transmitting data and an apparatus and method for receiving data in a wireless audio/video (WAV) system.

Related Art

Recently, demand for high-definition and high-quality images such as high definition (HD) images and ultra-high definition (UHD) images has increased in various fields. Since the amount of information or bits to be transmitted relatively increases as image data becomes high-definition and high-quality data, transmission cost may increase when image data is transmitted using a medium such as a conventional wired/wireless broadband line.

Meanwhile, the Institute of Electrical and Electronics Engineers (IEEE) 802.11ad standard is a high-speed wireless communication standard operating in a band of 60 GHz or higher. It has signal coverage of about 10 meters but can support throughput of 6 Gbps or more. Since it operates in a high frequency band, signal propagation is dominated by ray-like propagation. Signal quality can be improved as a transmit (TX) or receive (RX) antenna beam is aligned toward a strong spatial signal path. Currently, the IEEE 802.11ay standard, an evolved version of IEEE 802.11ad, is under development.

Established standards such as IEEE 802.11ad or ay series are based on multiple access and communication of a plurality of devices. Accordingly, data formats or frame formats used by a medium access control (MAC) layer or a physical layer of the IEEE 802.11ad or ay series include a plurality of control information fields for controlling and managing resources and operations of numerous devices. However, most applications of a wireless AV system to which the present disclosure pertains are based on 1:1 wireless communication (e.g., communication between a wireless set-top box and a wireless TV). If the wireless AV system is implemented using an existing standard method as it is, a plurality of control information fields included in a data format and a frame format of the existing standard may become unnecessary overhead that is discarded without being used.

Accordingly, there is a need for a method capable of improving communication performance of a wireless AV system by reducing overhead.

SUMMARY

The present disclosure provides a data transmission apparatus and reception apparatus in a wireless AV system.

The present disclosure also provides a data transmission apparatus and reception apparatus in a wireless AV system for improving communication performance of the wireless AV system by reducing overhead of MAC data or PHY data.

The present disclosure also provides a data transmission apparatus and reception apparatus for providing a frame check sequence (FCS) in units of segment based on the concept of an aggregated MAC protocol data unit (A-MPDU) in a wireless AV system.

The present disclosure also provides a data transmission apparatus and reception apparatus for supporting backward compatibility with IEEE 802.11ad or ay standards up to at least a first address (address1) of a MAC header in a wireless AV system.

The present disclosure also provides a data transmission apparatus and reception apparatus for minimizing a MAC dummy based on the concept of a short aggregated MAC service data unit (A-MSDU).

An aspect of the present disclosure provides an apparatus for transmitting data in a wireless AV system. The apparatus includes a processor configured to encode media data to generate a compressed bitstream, and a communication unit configured to fragment the compressed bitstream, to map the fragmented compressed bitstream to a medium access channel (MAC) service data unit (MSDU), to generate a MAC protocol data unit (MPDU) sequentially including a MAC header, a frame body, and a frame check sequence (FCS) regarding the MAC header for transmission of the MSDU, to generate a PHY protocol data unit (PPDU) sequentially including a preamble to which at least a part of the MAC header is mapped, at least one PHY service data unit (PSDU) to which the frame body and the FCS are mapped, and a training (TRN) field, and to transmit the PPDU frame through a wireless channel.

In an aspect, the MAC header may include only an RA field as a field related to an address.

In another aspect, 0 bit may be allocated to a service set ID (SSID) field in the MAC header.

In another aspect, the preamble to which at least a part of the MAC header is mapped may be an EDMG-header A.

In another aspect, at least a part of the MAC header may be the RA field, a length field, and a QoS field.

In another aspect, the communication unit may generate wireless AV frame parameters based on at least one of the RA field, the length field, and the QoS field and map the wireless AV frame parameters to an EDMG header A in the preamble.

In another aspect, the wireless AV frame parameters may include at least one of a field indicating whether the PPDU frame is a wireless AV data frame, a modified RA field based on an association ID (AID), an index field with respect to an A-MSDU size, and a field indicating whether the PPDU frame is used for reverse direction grant, and a field indicating a wireless AV tracking type.

In another aspect, the communication unit may map the wireless AV frame parameters to at least some bits of an MCS field in the EDMG header A.

In another aspect, the number of at least some bits of the MCS field may be determined by the number of spatial streams.

In another aspect, the communication unit may determine whether to perform retransmission in units of an MSDU of each sub-body based on an FCS regarding the frame body.

Another aspect of the present disclosure provides an apparatus for receiving data in a wireless audio video (AV) system. The apparatus may include a communication unit configured to receive a PHY protocol data unit (PPDU) frame through a wireless channel, to obtain a preamble, at least one PHY service data unit (PSDU), and a training (TRN) field from the PPDU frame, to obtain wireless AV frame parameters from at least a part of the preamble, to obtain a MAC protocol data unit (MPDU) frame from the PSDU, to obtain a MAC header, a frame body, and a frame check sequence (FCS) regarding the MAC header from the MPDU frame, to obtain a fragmented medium access channel (MAC) service data unit (MSDU) from the frame body, and to obtain a compressed bitstream from the fragmented MSDU, and a processor configured to decode the compressed bitstream to obtain media data.

In an aspect, the MAC header may include only an RA field as a field related to an address.

In another aspect, 0 bit may be allocated to a service set ID (SSID) field in the MAC header.

In another aspect, the MAC header may include the RA field, a length field, and a QoS field.

In another aspect, at least a part of the preamble may be an EDMG-header A.

In another aspect, the wireless AV frame parameters may include at least one of a field indicating whether the PPDU frame is a wireless AV data frame, a modified RA field based on an association ID (AID), an index field with respect to an A-MSDU size, and a field indicating whether the PPDU frame is used for reverse direction grant, and a field indicating a wireless AV tracking type.

In another aspect, the wireless AV frame parameters may be mapped to at least some bits of an MCS field in the EDMG header A.

In another aspect, the number of at least some bits of the MCS field may be determined by the number of spatial streams.

In another aspect, the communication unit may determine whether to perform retransmission in units of an MSDU of each sub-body based on an FCS regarding the frame body.

It is possible to secure radio resources for actually necessary data transmission by minimizing unnecessary overhead information (i.e., control related information in the MAC header) among wirelessly transmitted data, to improve a data transmission rate through reduction in overhead information, and to design a MAC/PHY data format or frame format customized for a wireless AV system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless display system according to an embodiment.

FIG. 2 is a block diagram showing a wireless data transceiving system according to an embodiment of the present disclosure.

FIG. 3 is a conceptual diagram of a case where the wireless data transceiving system according to an embodiment of the present disclosure is implemented according to an IEEE 802.11 series communication protocol.

FIG. 4 is a diagram illustrating various MPDU frame formats used in the IEEE 802.11ad standard according to an example.

FIG. 5 is a block diagram illustrating a wireless data transmission/reception system according to another embodiment.

FIG. 6 is an exemplary MPDU frame structure based on FIG. 5 .

FIG. 7 is another exemplary MPDU frame structure based on FIG. 5 .

FIG. 8 illustrates an MPDU frame according to another embodiment.

FIG. 9 is an exemplary MPDU frame structure based on FIG. 8 .

FIG. 10 is another exemplary MPDU frame structure based on FIG. 8 .

FIG. 11 is an example of results of simulation for comparing the performances of various MPDU frames.

FIG. 12 a is a PPDU frame of a physical layer to which an MPDU frame may be mapped according to an example.

FIG. 12 b is a PPDU frame of a physical layer to which an MPDU frame may be mapped according to another example.

FIGS. 13 a and 13 b are PPDU frames of a physical layer to which an MPDU frame may be mapped according to another example.

FIG. 14 is an example in which an MPDU frame is mapped to a PPDU frame.

FIG. 15 is an example in which an MPDU frame is mapped to an A-PPDU frame.

FIG. 16 is another example in which an MPDU frame is mapped to an A-PPDU frame.

FIG. 17 is another example of results of simulation for comparing the performances of various MPDU frames.

FIG. 18 is another example in which an MPDU frame is mapped to an A-PPDU frame.

FIG. 19 is another example in which an MPDU frame is mapped to an A-PPDU frame.

FIG. 20 is another example in which an MPDU frame is mapped to a PPDU frame.

FIG. 21 is another example of results of simulation for comparing the performances of various MPDU frames.

FIG. 22 illustrates a wireless AV data frame including a modified EDMG header A according to an embodiment.

FIG. 23 is another example of results of simulation for comparing the performances of various MPDU frames.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following detailed description illustrates embodiments of a device and method for transmitting wireless data and embodiments of a device and method for receiving wireless data that are provided according to the present disclosure. And, such embodiments do not represent the only forms of the present disclosure. The characteristics and features of the present disclosure are described with reference to exemplary embodiments presented herein. However, functions and structures that are similar or equivalent to those of the exemplary embodiments described in the present specification may be included in the scope and spirit of the present disclosure and may be achieved by other intended embodiments. Throughout the present specification, similar reference numerals will be used to refer to similar components or features. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In recent years, the design of display devices, such as TVs, has become important, and display panels have become thinner with the development and evolution of technologies for display panels, such as OLED. However, due to the thickness of a driving circuit that is required in order to drive a display panel, there have been restrictions (or limitations) in manufacturing and designing thinner display panels. Therefore, a technology that is capable of separating components excluding components that are mandatorily required to be physically and electrically connected to the display panel, from the display panel, and equipping the physically or electrically separated components to a separate device (hereinafter referred to as a “main device”) is being considered as a promising technology. In this case, a main device and a display device may be configured to exchange image signals and audio signals based on a wireless communication between the main device and the display device. The present disclosure relates to a wireless AV system, or a wireless display system being equipped with a main device and a display device that are provided as physically and/or electrically independent components, wherein media may be played (or reproduced) based on a wireless communication between the devices.

FIG. 1 is a block diagram of a wireless display system according to an embodiment of the present disclosure.

Referring to FIG. 1 , a wireless display system 10 may include a main device 10, a display panel device 200, and a remote control device 300.

The main device 100 may perform an operation of receiving an external signal in a wired or wireless format that is related to audio, video, pictures, images, multimedia, or at least one combination thereof, processing the received external signal by using various methods, so as to generate a data stream or a bitstream, and transmitting the generated data stream or bitstream to the display device 200.

In order to perform such operation, the main device 100 may include an external signal receiver 110, an external device interface unit 115, a storage unit 120, a main controller 130, a wireless communication unit 140, and a power supply unit 150.

The external signal receiver 110 may include a tuner 111, a demodulator 112, and a network interface unit 113.

The tuner 111 receives an external signal in a wired or wireless format that is related to audio, video, pictures, images, multimedia, or at least one combination thereof. For example, the tuner 111 may select a specific broadcast channel in accordance with a channel selection command and may receive a broadcast signal corresponding to the selected specific broadcast channel.

The demodulator 112 may separate the received broadcast signal to a video signal, an image signal, a picture signal, an audio signal, and a data signal related to a broadcast program. And, then, the demodulator 112 may reconstruct (or restore or recover) the separated video signal, image signal, picture signal, audio signal, and data signal to a format that can be outputted.

The external device interface unit 115 may receive an application or an application list of a nearby (or neighboring) external device and may deliver (or communicate) the application or application list to the main controller 130 or storage unit 120.

The external device interface unit 115 may provide a connection path between the wireless AV system 100 and an external device. The external device interface unit 115 may receive an external input signal including audio, video, pictures, images, multimedia, or at least one combination thereof from an external device, which is connected to the main device 100 via wired or wireless connection, and may then deliver the received external input signal to the main controller 130. The external device interface unit 115 may include multiple external input terminals. The multiple external input terminals may include an RF terminal, an RGB terminal, one or more High Definition Multimedia Interface (HDMI) terminals, a USB terminal, a component terminal, an AV terminal, a CI terminal.

An external device that is connectable to the external device interface unit 115 may be any one of a set-top box, a Bluray player, a DVD player, a gaming system, a sound bar, a smart phone, a PC, a USB memory, a home theater system. However, these are merely exemplary.

The network interface unit 113 may provide an interface for connecting the main device 100 to a wired/wireless network including an internet network. The network interface unit 113 may transmit or receive data to or from another user or another electronic device through an accessed network or another network that is linked to the accessed network.

Additionally, some content data stored in the main device 100 may be transmitted to a user or an electronic device, which is selected from other users or other electronic devices that are pre-registered in the main device 100.

The network interface unit 113 may access a predetermined webpage through an accessed network or another network that is linked to the accessed network. That is, the network interface unit 113 may transmit or receive data to or from a corresponding server by accessing a predetermined webpage through the network.

Also, the network interface unit 113 may receive contents or data provided from a content provider or a network operator. That is, the network interface unit 113 may receive contents such as movies, advertisements, games, VODs, and broadcast signals, which are provided from a content provider or a network provider, and related information through the network.

Additionally, the network interface unit 113 may receive firmware update information and update files provided from a network operator and may transmit data to an internet or content provider or a network operator.

The network interface unit 113 may select and receive a wanted application among applications that are open to public, through the network.

The storage unit 120 may store programs for performing processing and control of each signal within the main controller 130, and then the storage unit 120 may store signal-processed image, voice, or data signals.

Additionally, the storage unit 120 may perform a function for temporarily storing image, voice, or data signals that are inputted from the external device interface unit 115 or network interface unit 113, and the storage unit 120 may also store information related to a predetermined image through a channel memory function.

The storage unit 120 may store an application or an application list that is inputted from the external device interface unit 115 or network interface unit 113.

The main controller 130 may control the main device 100 by using a user instruction (or command) that is inputted through the remote control device 300, or by using an internal program, and may access a network in order to be capable of downloading an application or an application list that is wanted by a user to the main device 100.

The main controller 130 enables user-selected channel information to be outputted along with a processed image or audio signal through a display device 200 or an audio output unit 250.

Additionally, the main controller 130 enables an image signal or audio signal, which is inputted from an external device, e.g., a camera or camcorder, through the external device interface unit 115, to be outputted through the display device 200 or audio output unit 250 in accordance with according to an external device image playback instruction (or command) that is received through the remote control device 300.

The main controller 130 may perform a control operation so that content stored in the storage unit 120, received broadcast content, or externally input content can be played back (or reproduced). Such content may be configured in various formats, such as a broadcast image, an externally inputted image, an audio file, a still image, an accessed (or connected) web screen, a document file, and so on.

The main controller 130 may decode a video, an image, a picture, a sound, or data related to a broadcast program being inputted through the demodulator 112, the external device interface unit 115, or the storage unit 120. Then, the main controller 130 may process the decoded data in accordance with encoding/decoding methods supported by the display device 200. Thereafter, the main controller 130 may process the encoded data by using various video/audio processing methods, such as compression and encoding, so as to transmit the corresponding data through a wireless channel, thereby generating a data stream or bitstream. Finally, the main controller 130 may transmit the generated data stream or bitstream to the display device 200 through the wireless communication unit 140. Depending upon the embodiments, the main controller 130 may also bypass the decoded data, without encoding the decoded data in accordance with the encoding/decoding methods supported by the display device 200, and may directly transmit the decoded data to the display device 200 through the wireless communication unit 140.

The main controller 130 may be configured to implement the functions, procedures, and/or methods of a processor 1130 of a wireless data transmitting device 1100 that are to be described with reference to each embodiment of the present specification. Layers of the wireless interface protocol may be implemented in the processor 1130.

The wireless communication unit 140 may be operatively coupled to the main controller 130, for example, as a combination of a wireless communication chip and an RF antenna. The wireless communication unit 140 may receive a data stream or bitstream from the main controller 130, may generate a wireless stream by encoding and/or modulating the data stream or bitstream into a format that can be transmitted through a wireless channel, and may transmit the generated wireless stream to the display device 200. The wireless communication unit 140 establishes a wireless link, and the main device 100 and the display device 200 are connected through the wireless link. The wireless communication unit 140 may be configured based on various wireless communication modes, such as short-range wireless communication including Wi-Fi, Bluetooth, NFC, and RFID, or a mobile communication network (e.g., 3G, 4G, and 5G cellular networks). For example, the wireless communication unit 140 may perform communication by using a communication protocol, such as a standard of the IEEE 802.11 series.

The power supply unit 150 supplies power to the external signal receiver 110, the external device interface unit 115, the storage unit 120, the main controller 130, and the wireless communication unit 140. Methods for receiving power from an external source performed by the power supply unit 150 may include a terminal method and a wireless method. In case the power supply unit 150 receives power by using a wireless method, the power supply unit 150 may include a separate configuration in order to wirelessly receive power. For example, the power supply unit 150 may include a power pick-up unit configured to be magnetically coupled with an external wireless power transmitting device so as to receive wireless power, and a separate communication and control unit configured to perform communication with the wireless power transmitting device in order to receive wireless power and to control transmission and reception of wireless power.

The wireless communication unit 140 may also be wirelessly connected to the remote control device 300, thereby being capable of transferring (or delivering) signals inputted by the user to the main controller 130 or transmitter (or delivering) signals from the main controller 130 to the user. For example, the wireless communication unit 140 may receive or process control signals, such as power on/off, screen settings, and so on, of the main device 100 from the remote control device 300 or may process control signals received from the main controller 130 so that the processed signals can be transmitted to the remote control device 300 in accordance with various communication methods, such as Bluetooth, Ultra Wideband (WB), ZigBee, Radio Frequency (RF), or Infrared (IR) communication, and so on.

Additionally, the wireless communication unit 140 may deliver (or communicate) control signals that are inputted from a local key (not shown), such as a power key, a volume key, a setup key, and so on, to the main controller 130.

Subsequently, the display device 200 may process a wireless stream, which is received from the main device 100 through a wireless interface, by performing a reverse process of a signal processing operation that is performed by the main device 100, and, then, the display device 200 may output a display or audio (or sound). In order to perform such operation, the display device 200 may include a wireless communication unit 210, a user input interface unit 220, a panel controller 230, a display unit 240, an audio output unit 250, and a power supply unit 260.

The wireless communication unit 210 may be configured as a combination of a wireless communication chip and an RF antenna. The wireless communication unit 210 is connected to the wireless communication unit 140 of the main device 100 through a wireless link and performs wireless communication with the wireless communication unit 140 of the main device 100. More specifically, the wireless communication unit 210 receives a wireless stream from the wireless communication unit 140 of the main device 100, demodulates the received wireless stream, and transmits the demodulated wireless stream to the panel controller 230. The wireless communication unit 210 may be configured based on various wireless communication modes, such as short-range wireless communication including Wi-Fi, Bluetooth, NFC, and RFID, or a mobile communication network (e.g., 3G, 4G, and 5G cellular networks). For example, the wireless communication unit 210 may perform communication by using a communication protocol, such as a standard of the IEEE 802.11 series.

The panel controller 230 decodes a signal that is demodulated by the wireless communication unit 210 so as to reconstruct (or recover) a bitstream or data stream. At this point, in case the bitstream or data stream is a compressed stream, the panel controller 230 may decompress or reconstruct the bitstream or data stream. Thereafter, the panel controller 230 may output the bitstream or data stream as a video signal, an image signal, a picture signal, an audio signal, or a data signal related to a broadcast program, and may transmit the signals to the display unit 240, the audio output unit 250, and the user input interface unit 220.

The video signal, the picture signal, the image signal, and so on, that are inputted to the display unit 240 may be displayed as a picture corresponding to the inputted picture signal. Alternatively, the picture signal that is processed by the panel controller 230 may be transmitted back to the main device 100 through the wireless communication unit 210 and may then be inputted to an external output device through the external device interface unit 115 of the main device 100.

The audio signal that is processed by the panel controller 230 may be audio-outputted to the audio output unit 250. Moreover, the audio signal that is processed by the panel controller 230 may be transmitted back to the main device 100 through the wireless communication unit 210 and may then be inputted to an external output device through the external device interface unit 115 of the main device 100.

Meanwhile, the panel controller 230 may control the display unit 240 so as to display a picture (or image). For example, the panel controller 230 may perform control operation, so that a broadcast picture (or image) that is inputted through the tuner 111, an externally inputted picture (or image) that is inputted through the external device interface unit 115, a picture (or image) that is inputted through the network interface unit, or a picture (or image) that is stored in the storage unit 120 can be displayed on the display unit 240. In this case, the picture (or image) that is displayed on the display unit 240 may be a still picture (or image) or a video, and may be a 2D image or a 3D image.

The panel controller 230 may be configured to implement the functions, procedures, and/or methods of a processor 1230 included in a wireless data receiving device 1200, which will be described with reference to each embodiment of the present specification. Additionally, the processor 1230 may be configured to implement the functions, procedures, and/or methods of the wireless data receiving 1200 that will be described with reference to each embodiment of the present specification.

The user input interface unit 220 may transmit a signal that is inputted, by the user, to the panel controller 230 or may transmit a signal from the panel controller 230 to the user. For example, the user input interface 220 may receive and process control signals, such as power on/off, screen settings, and so on, of the display device 200 from the remote control device 300, or may process control signals received from the panel controller 230 so that the processed signals can be transmitted to the remote control device 300 in accordance with various communication methods, such as Bluetooth, Ultra Wideband (WB), ZigBee, Radio Frequency (RF), or Infrared (IR) communication, and so on.

The user input interface unit 220 may transmit a control signal, which is inputted through a local key (not shown), such as a power key, a volume key, a setup key, and so on, to the panel controller 230.

The power supply unit 260 supplies power to the wireless communication unit 210, the user input interface unit 220, the panel controller 230, the display unit 240, and the audio output unit 250. Methods for receiving power from an external source performed by the power supply unit 260 may include a terminal method and a wireless method. In case the power supply unit 260 receives power by using a wireless method, the power supply unit 260 may include a separate configuration in order to wirelessly receive power. For example, the power supply unit 260 may include a power pick-up unit configured to be magnetically coupled with an external wireless power transmitting device so as to receive wireless power, and a separate communication and control unit configured to perform communication with the wireless power transmitting device in order to receive wireless power and to control transmission and reception of wireless power.

The remote control device 300 performs an operation of remotely controlling various features of the main device 100 or the display device 200, such as power on/off, channel selection, screen setup, and so on. Herein, the remote control device 300 may also be referred to as a “remote controller (or remote)”.

Meanwhile, since the main device 100 and the display device 200, which are shown in FIG. 1 , are provided only as an example of one embodiment of the present disclosure, some of the illustrated components may be integrated or omitted, or other components may be added according to the specifications of the main device 100 and the display device 200, which are actually implemented. That is, as necessary, two or more components may be integrated into one component, or one component may be divided into two or more components. In addition, a function that is performed in each block is presented to describe an embodiment of the present disclosure, and a specific operation or device will not limit the scope and spirit of the present disclosure.

According to another embodiment of the present disclosure, unlike the example shown in FIG. 1 , the main device 100 may receive and play-back (or reproduce) an image (or picture) through the network interface unit 113 or the external device interface unit 115 without including the tuner 111 and the demodulator 112.

For example, the main device 100 may be implemented by being divided into an image processing device, such as a set-top box, for receiving broadcast signals or content according to various network services, and a content playback device for playing content input from the image processing device.

In this case, an operating method of the wireless AV system 10 according to an embodiment of the present disclosure that will hereinafter be described may be performed not only by the main device 100 and the display device 200, as described above with reference to FIG. 1 , but also by one of the divided image processing device, such as the set-top box, or content playback device, which includes an audio output unit 250.

In light of system input/output, the main device 100 may be referred to as a wireless source device that wirelessly provides a source, and the display device 200 may be referred to as a wireless sink device that wirelessly receives a source. The wireless source device and the wireless sink device may implement wireless display (WD) communication technologies that are compatible with standards such as wireless HD, wireless home digital interface (WHDI), WiGig, wireless USB, and Wi-Fi display (WFD, which also known as Miracast).

In light of the applications, the main device 100 may be integrated to a form that configures part of a wireless set-top box, a wireless gaming console, a wireless digital video disc (DVD) player, a wireless router, or the like. In this case, the main device 100 may be provided as a wireless communication module or a chip. The display device 200 may be integrated to a form that configures part of a user device or electronic device (e.g., a wireless TV, a wireless monitor, a wireless projector, a wireless printer, a wireless vehicle dashboard display, a wearable device, an augmented-reality (AR) headset, a virtual-reality (VR) headset, or the like) having a display panel so as to display an image and a video. In this case, the display device 200 may be provided in the form of a wireless communication module or chip.

The main device 100 and the display device 200 may be integrated to forms that configure parts of a mobile device. For example, the main device 100 and the display device 200 may be integrated into a mobile terminal including a smartphone, a smartpad, a tablet PC, or other types of wireless communication devices, a portable computer having a wireless communication card, a personal digital assistant (PDA), a portable media player, a digital image capturing device, such as a camera or camcorder, or other flash memory devices having wireless communication capabilities. In this case, the main device 100 and the display device 200 may be provided in the form of wireless communication modules or chips.

Smartphone users may perform streaming or mirroring of a video and an audio, which are outputted by the users' smartphones, tablet PCs, or other computing devices, to another device, such as a television or a projector, in order to provide a higher resolution display or other enhanced user experience.

As described above, the main device 100 may receive an external signal in a wired or wireless format that is related to a medium, such as audio, video, a picture, an image, multimedia, or at least one combination thereof, and the main device 100 may process the received external signal by using various methods, so as to generate a data stream or bitstream, and may transmit the data stream or bitstream to the display device 200 through a wireless interface.

Hereinafter, image (or picture)/video/audio data that are transmitted through a wireless interface will be collectively referred to as wireless data. That is, the main device 100 may wirelessly communicate with the display device 200 and may transmit wireless data. Therefore, in light of a wireless data transceiving system 1000, the main device 100 may be referred to as a wireless data transmitting device 1100, and the display device 200 may be referred to as a wireless data receiving device 1200. Hereinafter, the present disclosure will be described in more detail in light of the wireless data transceiving system 1000. Firstly, a detailed block diagram of the wireless data transceiving system 1000 will be illustrated.

FIG. 2 is a block diagram showing a wireless data transceiving system according to an embodiment of the present disclosure.

Referring to FIG. 2 , a wireless data transceiving system 1000 refers to a system that wirelessly transmits and receives a data stream. And, the wireless data transceiving system 1000 includes a wireless data transmitting 1100 and at least one wireless data receiving device 1200. The wireless data transmitting device 1100 is communicatively coupled to the at least one wireless data receiving device 1200.

According to an aspect, the data may be configured of an audio, a video, a picture, an image, multimedia, or at least one combination thereof.

According to another aspect, the data may include a bitstream in the form of a compressed audio, a bitstream in the form of a compressed video, a bitstream in the form of a compressed picture, a bitstream in the form of compressed multimedia, or at least one combination thereof. In this case, the wireless data transceiving system 1000 may also be referred to as a wireless compressed data stream transceiving system. Additionally, the wireless compressed data stream transceiving system 1000 may further include a functional or physical unit for compressing data.

Referring to the detailed configuration of each device, the wireless data transmitting device 1100 includes a processor 1130, a memory 1120, and a communication unit 1140, and the wireless data receiving device 1200 includes a communication unit 1210, a memory 1220, and a processor 1230.

The processor 1130 may be configured to implement the functions, procedures, and/or methods of the wireless data transmitting device 1100 that are to be described with reference to each embodiment of the present specification. Also, the processor 1230 may also be configured to implement the functions, procedures, and/or methods of the wireless data receiving device 1200 that are to be described with reference to each embodiment of the present specification. Layers of the wireless interface protocol may be implemented in the processors 1130 and 1230.

In light of the display system in FIG. 1 , the processor 1130 may be configured to perform the function of the main controller 130. For example, the processor 1130 may decode a video, an image, a picture, a sound, or data related to a broadcast program that are inputted through the demodulator 112, the external device interface unit 115, or the storage unit 120, may process the decoded data by using various video/audio processing methods, such as compression and encoding, so as to transmit the data through a wireless channel, thereby generating a data stream or bitstream, and may transmit the generated data stream or bitstream to the display device 200 through the communication unit 1140.

The memories 1120 and 1220 are operatively coupled with the processors 1130 and 1230 and store various types of information for operating the processors 1130 and 1230.

The communication units 1140 and 1210 are operatively coupled with the processors 1130 and 1230 and wirelessly transmit and/or receive data. The communication units 1140 and 1210 establish a wireless link 11, and the wireless data transmitting device 1100 and the wireless data receiving device 1200 are inter-connected through the wireless link 11. The communication units 1140 and 1210 may be configured based on various wireless communication modes, such as short-range wireless communication including Wi-Fi, Bluetooth, NFC, and RFID, or a mobile communication network (e.g., 3G, 4G, and 5G cellular networks). For example, the wireless communication units 1140 and 1210 may perform communication by using a communication protocol, such as a standard of the IEEE 802.11 series.

FIG. 3 is a conceptual diagram of a case where the wireless data transceiving system according to an embodiment of the present disclosure is implemented according to an IEEE 802.11 series communication protocol.

Referring to FIG. 3 , a wireless data transceiving system 20 in (A) of FIG. 3 may include at least one basic service set (hereinafter referred to as ‘BSS’) 21 and 25. A BSS is a set consisting of an access point (hereinafter referred to as ‘AP’) and a station (STA) that are successfully synchronized and, thus, capable of communicating with each other. Herein, the BSS does not refer to a specific region (or area).

For example, a first BSS 21 may include a first AP 22 and one first STA 21-1. A second BSS 25 may include a second AP 26 and one or more STAs 25-1 and 25-2. Herein, the first AP 22 may correspond to the communication unit 1140 of FIG. 2 , and the one or more STAs 25-1 and 25-2 may correspond to the communication unit 1210 of FIG. 2 .

An infrastructure BSS 21 and 25 may include at least one STA, APs 22 and 26 providing a distribution service, and a distribution system (DS) 27 connecting multiple APs.

The distribution system 27 may implement an extended service set (hereinafter referred to as ‘ESS’) 28, which is extended by being connected to multiple BSSs 21 and 25. The ESS 28 may be used as a term indicating one network that is configured by connecting one or more APs 22 and 26 through the distribution system 27. At least one AP being included in one ESS 28 may have a same service set identification (hereinafter referred to as ‘SSID’).

A portal 29 may perform the role of a bridge, which connects the wireless LAN network (IEEE 802.11) with another network (e.g., 802.X).

In a WLAN having the structure shown in (A) of FIG. 3 , a network between the APs 22 and 26 and a network between the APs 22 and 26 and the STAs 21-1, 25-1, and 25-2 may be implemented.

Meanwhile, unlike the system shown in (A) of FIG. 3 , the wireless data transceiving system 30 shown in (B) of FIG. 3 may be capable of performing communication by establishing a network between the STAs without any APs 22 and 26. A network that is capable of performing communication by establishing a network between the STAs without any APs 22 and 26 is defined as an Ad-Hoc network or an independent basic service set (hereinafter referred to as ‘IBSS’).

Referring to (B) of FIG. 3 , the wireless data transceiving system 30 is a BSS that operates in the Ad-Hoc mode, i.e., an IBSS. Since the IBSS does not include any AP, a centralized management entity that performs a management function at the center does not exist. Therefore, in the wireless data transceiving system 30, STAs 31-1, 31-2, 31-3, 32-4, and 32-5 are managed in a distributed manner. Here, the STAs 31-1, 31-2, 31-3, 32-4, and 32-5 may correspond to the communication unit 1140 or the communication unit 1210 of FIG. 2 .

All STAs 31-1, 31-2, 31-3, 32-4, and 32-5 included in the IBSS may be configured as mobile STAs and are not allowed to access a distributed system. All of the STAs included in the IBSS establish a self-contained network.

An STA that is mentioned in the present specification is a random functional medium including a medium access control (hereinafter referred to as ‘MAC’) and a physical layer interface for a wireless medium according to the regulations of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and may be used to broadly refer to both an AP and a non-AP STA.

An STA that is mentioned in the present specification may be referred to by using various terms, such a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, and, simply, a user.

Referring back to FIG. 2 , a communication channel that is established by the communication units 1140 and 1210 may be a network communication channel. In this case, the communication units 1140 and 1210 may establish a tunneled direct link setup (TDLS) in order to avoid or reduce network congestion. Wi-Fi Direct and TDLS are used for setting up relatively short-range communication sessions. The communication channel that establishes a wireless link 11 may be a communication channel of a relatively short range or a communication channel that is implemented by using a physical channel structure, such as Wi-Fi using a variety of frequencies including 2.4 GHz, 3.6 GHz, 5 GHz, 60 GHz, or ultra-wideband (UWB), Bluetooth, and so on.

While techniques disclosed in the present specification may generally be described in relation with communication protocols, such as the IEEE 802.11 series standard, it will be apparent that aspects of such techniques may also be compatible with other communication protocols. Illustratively and non-restrictively, wireless communication between the communication units 1140 and 1210 may use orthogonal frequency-division multiplexing (OFDM) schemes. Other various wireless communication schemes including, but not limited to, time-division multiple access (TDMA), frequency-division multiple access (FDMA), code-division multiple access (CDMA), or any random combination of OFDM, FDMA, TDMA, and/or CDMA may also be used.

The processors 1130 and 1230 may include an application-specific integrated circuit (ASIC), a different chipset, a logic circuit, and/or a data processor. The memories 1120 and 1220 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and/or another storage device. The communication units 1140 and 1210 may include a baseband circuit for processing radio frequency signals. When an embodiment is implemented as software, the techniques described herein may be implemented as a module (e.g., a procedure, function, and so on) that performs the functions described in the present specification. The module may be stored in the memories 1120 and 1220 and may be executed by the processors 1130 and 1230. The memories 1120 and 1220 may be implemented inside the processors 1130 and 1230. Alternatively, the memories 1120 and 1220 may be implemented outside of the processors 1130 and 1230, and the memories 1120 and 1220 may be communicatively connected to the processors 1130 and 1230 via various well-known means that are disclosed in this technical field.

In light of the input/output of a data stream, the wireless data transmitting device 1100 may be referred to as a wireless source device that wirelessly provides a source, and the wireless data receiving device 1200 may be referred to as a wireless sink device that wirelessly receives a source. The wireless source device and the wireless sink device may implement wireless display (WD) communication technologies that are compatible with standards such as wireless HD, wireless home digital interface (WHDI), WiGig, wireless USB, and Wi-Fi display (WFD, which also known as Miracast).

In light of the applications, the wireless data transmitting device 1100 may be integrated to a form that configures part of a wireless set-top box, a wireless gaming console, a wireless digital video disc (DVD) player, a wireless router, or the like. In this case, the wireless data transmitting device 1100 may be provided as a wireless communication module or a chip. And, the wireless data receiving device 1200 may be integrated to a form that configures part of a user device or electronic device (e.g., a wireless TV, a wireless monitor, a wireless projector, a wireless printer, a wireless vehicle dashboard display, a wearable device, an augmented-reality (AR) headset, a virtual-reality (VR) headset, or the like) having a display panel so as to display an image and a video. In this case, the wireless data receiving device 1200 may be provided in the form of a wireless communication module or chip.

The wireless data transmitting device 1100 and the wireless data receiving device 1200 may be integrated to forms that configure parts of a mobile device. For example, the wireless data transmitting device 1100 and the wireless data receiving device 1200 may be integrated into a mobile terminal including a smartphone, a smartpad, a tablet PC, or other types of wireless communication devices, a portable computer having a wireless communication card, a personal digital assistant (PDA), a portable media player, a digital image capturing device, such as a camera or camcorder, or other flash memory devices having wireless communication capabilities. In this case, the wireless data transmitting device 1100 and the wireless data receiving device 1200 may be provided in the form of wireless communication modules or chips.

Smartphone users may perform streaming or mirroring of a video and an audio, which are outputted by the users' smartphones, tablet PCs, or other computing devices, to another device, such as a television or a projector, in order to provide a higher resolution display or other enhanced user experience.

FIG. 4 is a diagram illustrating various MPDU frame formats used in the IEEE 802.11ad standard according to an example. A MAC protocol data unit (hereinafter MPDU) is a unit of data exchanged between two peer MAC layers or MAC entities. An MPDU frame may be simply called an MPDU or MAC data.

Referring to FIG. 4 , the MAC layer receives a MAC service data unit (MSDU) from a higher layer. In addition, the MAC layer may generate various types of MPDU frames including a MAC header, a frame body, and a frame check sequence (FCS). In the MPDU frame, the MAC header, the frame body, and the FCS are sequentially arranged from left to right and are passed to a physical layer convergence procedure (PLCP) in this order.

The MAC header includes control information fields for transmission, control, or management of the MPDU frame.

The frame body is a data field provided for moving data of a higher layer and may include, for example, an MSDU or an MSDU fragment, a subheader, and a trailer. The subheader may be located at the front end of the MSDU or MSDU fragment, and the trailer may be located at the rear end of the MSDU or MSDU fragment. The frame body may be composed of a plurality of subframes.

The FCS is used for a receiver to check the integrity of a frame. All fields of the MAC header and the frame body may be included in the FCS, or a part (i.e., MSDU) of the frame body may be included in the FCS. The receiver may calculate the FCS from a received frame, may compare the same with the FCS of the corresponding frame, and if the two match each other, may determine that the frame has been normally received. The FCS may be referred to as a cyclic redundancy check (CRC).

As an example, the MPDU frame according to (a) of FIG. 4 indicates a general MPDU frame type including one MSDU for each MPDU. That is, MPDU 1 includes MSDU 1 and MPDU N includes MSDU N. The MPDU frame includes a MAC header at the front end of the frame body. The MAC header may include, for example, control information fields such as a frame control (FC) field, a duration (Dur.) field, a receiver address (RA) field, a transmitter address (TA) field, a BSSID field, a sequence (Seq.) field, and a quality of service (QoS) field.

The FC field is 2 bytes, is provided at the start position of the MAC header, and defines a protocol version and the type of the current MPDU frame (data frame, management frame, or control frame).

The duration field is 2 bytes, follows the frame control field, and indicates a time (in μs) that is expected to be used during transmission of the MPDU frame. The duration field may be used to set a network allocation vector (NAV), which is a value serving as a kind of medium use reservation timer.

The RA field is a MAC address identifier of an intended receiver with respect to the current MPDU frame or a MAC address identifier indicating which wireless device processes the current MPDU frame, and may be, for example, 6 bytes (48 bits). If a receiver address field indicates the address of an STA, the receiver address may be the same as a destination address. In some cases, a destination address (DA) field such as a client/server may be inserted instead of the RA field.

The TA field is a MAC address identifier of a transmitter that transmits the current MPDU frame and may be, for example, 6 bytes (48 bits). In some cases, a source address (SA) field such as a client/server may be inserted instead of the TA field.

The BSSID field is an ID for identifying a basic service set and may be, for example, 2 bytes.

The sequence field is used when a segmented MSDU is reassembled or a duplicate frame is discarded and may be, for example, 2 bytes. A higher layer frame (i.e. MSDU) is given a fragment number and a sequence number while being delivered to the MAC layer for transmission, and the sequence field indicates such a fragment number and/or sequence number.

As another example, the MPDU frame according to (b) and (c) of FIG. 4 indicates an MPDU frame type including a plurality of MSDUs in which MPDUs are aggregated. That is, a single MPDU frame includes a plurality of aggregated MSDUs 1, 2, . . . , N. MPDU frames of types (b) and (c) have one MAC header commonly applied to a plurality of MSDUs, and further include specific control information (hereinafter, MSDU-specific control information) for each MSDU.

For example, the MPDU frame of type (b) includes a MAC header (FC field, Dur. field, RA field, TA field, BSSID field, sequence field, QoS field) and MSDU specific control information (destination address (DA) field, a source address (SA) field, a length (Len) field, and padding). A set of MSDU-specific control information may be referred to as a subheader. Here, the DA field is control information indicating the destination address of the corresponding MSDU, the SA field is control information indicating the source address of the corresponding MSDU, and the length field is control information indicating the length of the corresponding MSDU. The padding is dummy control information that is added to an MSDU having a variable length to maintain the overall length constant.

Meanwhile, the MPDU frame of the type (c) includes a length field and padding as MSDU specific control information. The difference between the types (b) and (c) is the presence or absence of the DA field and the SA field in the MSDU specific control information. Since the type (c) does not have the DA field and SA field as compared to the type (b), the type (b) may be called an MPDU frame based on basic A-MSDU and type (c) may be called an MPDU based on short A-MSDU.

The MPDU frame of the type (a) is generated in such a manner that a MAC header is added to each MSDU, whereas the MPDU frames of the types (b) and (c) are generated in such a manner that a single MAC header commonly applied to a plurality of aggregated MSDUs is added. Accordingly, at the time of transmitting the same number of MSDUs, control information fields with a smaller number of bits are transmitted when MPDU frames of the types (b) and (c) are used than when MPDU frames of the type (a) are used.

Finally, the MPDU frame of the type (d) is an aggregated MPDU (hereinafter, referred to as A-MPDU) frame, which is generated in such a manner that a delimiter field and padding are inserted between MPDUs of the type (a) and the MPDUs are combined.

Meanwhile, MPDU frames of the types (a) to (d) have different characteristics in terms of whether block ACK is supported and retransmission efficiency. For example, MPDU frames of the types (b) and (c) do not support block ACK, whereas MPDU frames of the type (d) may support block ACK.

The following table shows the number of bytes of control information fields inserted into MPDU frames of the types (a) to (d) and whether block ACK is supported.

TABLE 1 Total MPDU control information Dummy for WAV frame MSDU field size when the 0.5 ms buffer type type number of MSDUs is N case (1.54 MB) Note (a) MSDU 30*N bytes 30*1 = 30 bytes @ ACK is applicable, MPDU 1.5 MB Single and retransmission MSDU efficiency decreases (b) Basic A- 30 + 14*N bytes 30 + 14*205 = Block Ack is not MPDU MSDU 2,900 bytes @ supported 7920 MSDU Len (c) Short A- 30 + 2*N bytes 30 + 2*205 = Block Ack is not MPDU MSDU 440 bytes @ supported 7920 MSDU Len (d) A- MSDU 34*N bytes 34*205 = There are many MPDU 8,970 bytes @ dummies. Block Ack 7920 MSDU Len is supportable => retransmission efficiency increases

Referring to Table 1, for example, in the case of an MPDU frame of the type (a), the number of bytes used as the control information fields is 30 bytes (2 bytes (FC field)+2 bytes (Dur. field)+6 bytes (RA field)+6 bytes (TA field)+6 bytes (BSSID field)+2 bytes (sequence field)+2 bytes (QoS field)+4 bytes (FCS)) per MSDU. Therefore, when the MPDU frame of the type (a) is used to transmit N MSDUs, a total of 30*N bytes is used as the control information fields.

When the types (a) to (d) are compared, bandwidths occupied by the control information fields for the types are also different because the numbers of bits used as the control information field are different. Control information fields added other than the MSDU are essential for system management and control, but they are not user data and thus the more and larger the control information fields, the lower the actual user data transmission speed and throughput. Conversely, when unnecessary control information fields are removed, the transmission speed and yield of actual user data can be improved.

For example, in most cases, applications of the wireless AV system to which the present disclosure pertains are based on 1:1 wireless communication (e.g., communication between a main body apparatus 100 and a display apparatus 200). That is, if the main body apparatus 100 is a wireless data transmission apparatus 1100, the display apparatus is a wireless data reception apparatus 1200, and if the display apparatus 200 is the wireless data transmission apparatus 1100, the main body apparatus 100 operates as the wireless data reception apparatus 1200. Such a wireless AV transmission environment provides a state in which the wireless data transmission apparatus 1100 and the reception apparatus 1200 are specified or fixed (i.e., a one-to-one connection state).

As described above, when the wireless data transmission apparatus 1100 and the reception apparatus 1200 are mutually specified or fixed, some MAC header information prepared for controlling a many-to-many connection or multiple access environment is unnecessary. That is, from the viewpoint of the transmission rate or yield of user data in the wireless AV system, a significant number of control information fields included in MPDU frames of the types (a) to (d) may be regarded as unnecessary overhead or dummy data that wastes a bandwidth. That is, the wireless AV system can operate even if the control information fields included in the MAC headers of MPDU frames of the types (a) to (3) are omitted or removed, which are not essential for the wireless AV system.

Accordingly, an embodiment of the present disclosure provides a method for designing a MAC frame and/or a PHY frame that improve the yield of a wireless AV system by reducing and/or minimizing overhead (or dummy data) of MAC data (i.e., MPDU) in the wireless AV system and apparatuses and methods for transmitting and/or receiving the MAC frame and/or the PHY frame.

Another embodiment of the present disclosure also provides a method for designing a MAC frame and/or a PHY frame for reducing data retransmission time/delay in a wireless AV system and apparatuses and methods for transmitting and/or receiving the MAC frame and/or the PHY frame. Since the wireless AV system has characteristics sensitive to time/delay, it is necessary to support block ACK during packet error recovery and retransmission. Accordingly, there is a need for a method for designing a MAC frame and/or a PHY frame capable of performing error recovery and retransmission in small data or segment units, and apparatuses and methods for transmitting and/or receiving the MAC frame and/or the PHY frame. An MPDU frame according to an example may provide an FCS in units of a segment or units of an MSDU based on the MPDU (i.e., A-MPDU) frame of the type (d).

In addition, another embodiment of the present disclosure provides a method for designing a MAC frame and/or a PHY frame providing backward compatibility in a wireless AV system and apparatuses and methods for transmitting and/or receiving the MAC frame and/or the PHY frame. The wireless AV system according to a third embodiment should not affect the operations of other devices (i.e., STAs or APs, hereinafter legacy stations) according to a short-range communication standard (e.g., IEEE 802.11 series) using the same unlicensed band.

An MPDU frame and a PPDU frame according to the present disclosure may be according to each of the above embodiments or a combination of two or more thereof. Hereinafter, the MPDU frame or the PPDU frame according to various embodiments of the present disclosure may be collectively referred to as a wireless AV data frame.

First, MPDU frames are classified according to the location where an FCS regarding a MAC header is disposed, as shown in FIG. 5 and FIG. 8 . FIG. 5 is an MPDU frame in which the FCS regarding the MAC header (or MPDU header) is disposed at the end of the MAC header and FIG. 8 is an MPDU frame in which the FCS regarding the MAC header (or MPDU header) is disposed at the end of the MPDU frame.

FIG. 5 illustrates an MPDU frame according to an embodiment.

Referring to FIG. 5 , the MPDU frame includes a MAC header, an FCS regarding the MAC header, and a frame body. The frame body may include a plurality of sub-bodies (sub-body 1, sub-body 2, . . . , sub-body n−1, and sub-body n).

The MPDU frame of FIG. 5 may have the same structure as that in FIG. 6 to FIG. 8 depending on how the MAC header and the frame body are configured.

FIG. 6 is an exemplary MPDU frame structure based on FIG. 5 .

Referring to FIG. 6 , a first candidate (Candi.1) MPDU frame includes a MAC header and a frame body. The MAC header includes an FC field, a duration field, an RA field, a TA field, a BSSI field, a sequence field, a QoS field, and an FCS regarding the MAC header sequentially from the left where the MAC header starts to the right. Here, the size of each control information field included in the MAC header may be the aforementioned number of bytes of each control information field of FIG. 6 .

The frame body includes a plurality of sub-bodies (sub-body 1, . . . , sub-body n). Here, each sub-body includes a length (len) field indicating the length of an MSDU included in the corresponding sub-body, a sequence field indicating the sequence of the corresponding sub-body (or MSDU), an MSDU, and an FCS regarding the corresponding sub-body sequentially from the left where the corresponding sub-body starts to the right. The size of each control information field included in the sub-body may be the aforementioned number of bytes of each control information field of FIG. 6 . For example, the MSDU is aligned or disposed after 4 bytes (2 bytes of the length field+2 bytes of the sequence field) from the beginning of each sub-body. The size of the MSDU may be independently determined by the length field of each sub-body, and the MSDUs of the sub-bodies may have the same size or different sizes.

Since the FCS is attached to each sub-body (or each MSDU), the first candidate MPDU frame can support error checking (i.e., block ACK or a method similar to block ACK) in units of a segment (i.e., MSDU).

FIG. 7 is another exemplary MPDU frame structure based on FIG. 5 .

Referring to FIG. 7 , a second candidate (Candi.2) MPDU frame includes a MAC header and a frame body. The MAC header includes an FC field, a duration field, an RA field, a TA field, a BSSI field, a length (len) field, a QoS field, and an FCS regarding the MAC header sequentially from the left where the MAC header starts to right. Here, the size of each control information field included in the MAC header may be the aforementioned number of bytes of each control information field of FIG. 7 .

The length field indicates the size of the MSDU in each sub-body disposed following the MAC header. When the second candidate MPDU frame is compared with the first candidate MPDU frame, the sequence field of the MAC header is replaced with the length field, and each sub-body does not include the length field. That is, the MAC header includes the length field and each sub-body does not include the length field. Accordingly, there is a constraint that the sizes of all MSDUs are set to be equal by one length field included in the MAC header, whereas the length field of 2 bytes is omitted in each sub-body, and thus 2(n−1) bytes can be saved. By allocating the number of bytes saved by removing the length field to user data MSDU, it is possible to increase the transmission yield of the user data.

Since the FCS is attached to each sub-body (or each MSDU), the first candidate MPDU frame can support error checking (i.e., block ACK or a method similar to block ACK) in units of a segment (i.e., MSDU).

Meanwhile, the size of each control information field in each sub-body may be the aforementioned number of bytes of each control information field of FIG. 7 . For example, the MSDU is aligned or disposed after 2 bytes (sequence field) from the beginning of each sub-body.

FIG. 8 illustrates an MPDU frame according to another embodiment. Unlike FIG. 5 , this is an MPDU frame including an FCS regarding the MAC header at the end of the MPDU frame.

Referring to FIG. 8 , the MPDU frame includes a MAC header, a frame body, and an FCS regarding the MPDU frame. The frame body may include a plurality of sub-bodies (sub-body 1, sub-body 2, . . . , sub-body n−1, and sub-body n).

The MPDU frame of FIG. 8 may have the same structure as that in FIG. 9 and FIG. 10 according to how the MAC header and the frame body are configured.

FIG. 9 is an exemplary MPDU frame structure based on FIG. 8 .

Referring to FIG. 9 , a third candidate (Candi.3) MPDU frame includes a MAC header, a frame body, and an FCS regarding the MAC header. The MAC header includes an FC field, a duration field, an RA field, a TA field, a BSSI field, a length (len) field, a QoS field, and an FCS regarding the MAC header sequentially from the left where the MAC header starts to the right. Here, the size of each control information field included in the MAC header may be the aforementioned number of bytes of each control information field of FIG. 9 .

The length field indicates the size of the MSDU in each sub-body disposed following the MAC header. Accordingly, there is a constraint that the sizes of all MSDUs are set to be equal by one length field included in the MAC header, whereas the length field of 2 bytes is omitted in each sub-body, and thus 2(n−1) bytes can be saved. By allocating the number of bytes saved by removing the length field to user data MSDU, it is possible to increase the transmission yield of the user data.

Since the FCS is attached to each sub-body (or each MSDU), the first candidate MPDU frame can support error checking (i.e., block ACK or a method similar to block ACK) in units of a segment (i.e., MSDU).

Meanwhile, the size of each control information field in each sub-body may be the aforementioned number of bytes of each control information field of FIG. 9 . For example, the MSDU is aligned or disposed after 2 bytes (sequence field) from the beginning of each sub-body.

FIG. 10 is another exemplary MPDU frame structure based on FIG. 8 .

Referring to FIG. 10 , a fourth candidate (Candi.4) MPDU frame includes a MAC header, a frame body, and an FCS regarding the MAC header. The MAC header includes an FC field, a duration field, an RA field, a TA field, a BSSI field, a length (len) field, and a QoS field sequentially from the left, where the MAC header starts, to the right. Here, the size of each control information fields included in the MAC header may be the aforementioned number of bytes of each control information field of FIG. 10 .

When the fourth candidate MPDU frame is compared with the third candidate MPDU frame, the FCS in the MAC header is removed.

Since the FCS is attached to each sub-body (or each MSDU), the first candidate MPDU frame can support error checking (i.e., block ACK or a method similar to block ACK) in units of a segment (i.e. MSDU).

Meanwhile, the size of each control information field in each sub-body may be the aforementioned number of bytes described in each control information field of FIG. 10 . For example, the MSDU is aligned or disposed after 2 bytes (sequence field) from the beginning of each sub-body.

Table 2 shows the performance of the first to fourth candidate MPDU frames in terms of whether block ACK is supported, backward compatibility with legacy stations, and increase or decrease in the number of bits.

TABLE 2 Total MPDU Whether control information Dummy for 0.5 ms frame block Ack is Backward field size when the Buf. (1.54 MB) @ type supported compatibility number of MSDUs is N 7920 bytes MSDU Len Conventional No Yes 30 + 2*N bytes 30 + 2*205 = 440 bytes A-MSDU First candidate Yes No 30 + 8*N bytes 30 + 8*205 = 1,670 bytes MPDU frame Second candidate Yes No 30 + 6*N bytes 30 + 6*205 = 1,260 bytes MPDU frame Third candidate Yes Yes 34 + 6*N bytes 34 + 6*205 = 1,264 bytes MPDU frame Fourth candidate Yes Yes 30 + 6*N bytes 30 + 6*205 = 1,260 bytes MPDU frame

Referring to Table 2, since the FCS is added to each sub-body in the first to fourth candidate MPDU frames, error checking (or block ACK) in units of small data (or in units of a segment unit or MSDU) is possible. However, since a 4-byte FCS is added to each sub-body to support block ACK, the number of bits may be increased as compared to an MPDU frame based on the conventional A-MSDU. Meanwhile, the first and second candidate MPDU frames do not include the FCS at the end of the MPDU frame and thus have difficulty supporting backward compatibility with legacy stations, whereas the third and fourth candidate MPDU frames include the FCS at the end of the MPDU frame and thus can support backward compatibility with legacy stations.

In the third and fourth candidate MPDU frames, an error checking (i.e., CRC) method using the FCS regarding the MAC header is as follows.

As an example, if a cyclic redundancy check (CRC) of the FCS regarding the MAC header is OK, CRCs of all MSDUs included in the corresponding MPDU may be treated as OK. If the CRC of the FCS regarding the MAC header is NOK (not OK), the CRCs of all MSDUs included in the corresponding MPDU may be treated as NOK. In this case, OK or NOK for each MSDU may be ignored by the CRC of the FCS regarding each MSDU.

As another example, retransmission may be performed based on OK or NOK by the CRC of the FCS for each MSDU. For example, even in the case of OK according to the CRC of the FCS for the MAC header, if a CRC of an FCS for a specific MSDU is NOK, retransmission of the specific MSDU may be performed. Further, even in the case of OK according to the CRC of the FCS for the MAC header, if a CRC of an FCS for a specific MSDU is NOK, retransmission of the specific MSDU may be performed.

The first to fourth candidate MPDU frames disclosed in FIGS. 6, 7, 9 and 10 are MPDU frames designed based on the A-MSDU. Hereinafter, an A-MPDU frame designed based on the MSDU will be disclosed.

Hereinafter, the present disclosure provides a criterion for distinguishing between a control information field essential for a wireless AV system and a control information field that is not essential for the wireless AV system. However, the technical spirit of the present disclosure does not limit a specific application to the wireless AV system.

The wireless AV system is based on a one-to-one service set or a personal basic service set (PBSS) due to characteristics of applications. That is, the wireless AV system is in a state in which a wireless data transmitter and receiver are specified or in a state in which the transmitter and the receiver are already mutually known.

Accordingly, a control information field for identification of the transmitter or the receiver can be implicitly known between the transmitter and the receiver even if it is not informed through an explicit signal. For example, in a wireless AV transmission environment, the wireless data transmission apparatus 1100 may be implicitly specified even if a transmitter address is not notified as an explicit signal. That is, in the wireless AV system, the transmitter address field is not an essential element but an optional element.

From the same point of view, the receiver address field may also be implicitly specified in a wireless AV transmission environment and thus may be omitted. However, since an MPDU frame in which the receiver address field is omitted is also transmitted to other devices (hereinafter referred to as legacy STAs) conforming to IEEE 802.11 standards, it may affect legacy stations such as causing malfunction of decoding of legacy stations. Therefore, in order to secure backward compatibility with legacy stations, it is desirable that the receiver address field be not omitted.

In addition, the BSSID is an identifier for distinguishing different BSSs in the network, and the advantage of using the BSSID is filtering. Different networks may overlap physically or in coverage, and data transmissions occurring in another overlapping network do not need to be received. Since the wireless AV system is based on a one-to-one service set or PBSS due to characteristics of applications, the BSSID field in the wireless AV system is not an essential element but an optional element.

However, in omitting non-essential elements in the MAC header in the wireless AV system, backward compatibility with legacy stations must be satisfied.

As an example, fields up to the first address information field of the MAC header may not be changed and fields subsequent to the first address information field may be omitted such that the MAC header is reduced. Accordingly, backward compatibility with IEEE 802.11ad or ay standards can be maintained.

FIG. 11 is an example of results of simulation for comparing the performances of various MPDU frames.

Referring to FIG. 11 , TRX time of the MPDU frames of (a), (d), and (c) of FIG. 4 which correspond to the legacy MPDU frame are compared with TRX time of the second candidate MPDU frame (upper table) and compared with MAC dummy (lower table).

Hereinafter, a method of mapping the MPDU frame according to FIG. 5 to FIG. 11 to a physical layer in order to transmit the MPDU frame and a transmission method will be disclosed.

A procedure for transmitting the MPDU frame as shown in FIGS. 5 to 11 at a transmitting side that wants to transmit the MPDU frame includes a step in which a MAC layer of the transmitting side generates the MPDU frame, a step in which the MAC layer of the transmitting side provides the MPDU frame to a physical layer that is a lower layer as a physical service data unit (PSDU), a step in which the physical layer of the transmitting side generates a physical protocol data unit (PPDU) frame including the PSDU, and a step in which the physical layer of the transmitting side transmits the PPDU frame to a physical layer of a receiving side.

A procedure for receiving the MPDU frame as shown in FIGS. 5 to 11 at a receiving side that wants to receive the MPDU frame includes a step in which a physical layer of the receiving side receives a PPDU frame from a physical layer of a transmitting side, a step in which the physical layer of the receiving side provides a PSDU to the MAC layer of the receiving side, and a step in which the MAC layer of the receiving side extracts the MPDU frame from the PSDU.

In the present disclosure, a source is defined as a wireless data transmission apparatus 1100 and a sink is defined as a wireless data reception apparatus 1200 based on a direction in which user data such as an image signal and a sound signal is transmitted. However, data communication according to the present embodiment is based on two-way communication, and since the sink can transmit an MPDU or PPDU required for control or management to the source, the transmitting side and the receiving side may be reversed. Accordingly, the present disclosure includes both a case where the transmitting side is the wireless data transmission apparatus 1100 and the receiving side is the wireless data reception apparatus 1200 and a case where the transmitting side is the wireless data reception apparatus 1200 and the receiving side is the wireless data transmission apparatus 1100.

Meanwhile, the physical layer may generate a PPDU or aggregate individual PPDUs to generate an aggregated PPDU (A-PPDU). That is, the wireless data transmission apparatus 1100 or the wireless data reception apparatus 1200 may generate a PPDU or aggregate individual PPDUs to generate an A-PPDU.

FIG. 12 a is a PPDU frame of a physical layer to which an MPDU frame may be mapped according to an example. This is a general PPDU frame.

Referring to FIG. 12 a , when the PPDU frame is represented as a logical bit level, it may include L-STF (legacy-short training field), L-CEF (legacy-channel estimation field), L-header (legacy-header), EDMG-header A (enhanced directional multi-gigabit-header A), EDMG-STF, EDMG-CEF, EDMG-header B, data, and TRN, and these fields may be optionally included according to PPDU type (e.g., SU PPDU, MU PPDU, etc.). The L-STF may include a training signal. The L-header may include control information for a first legacy station (e.g., a station supporting IEEE802.11ad), the EDMG-header may include control information for a second legacy station (e.g., a station supporting IEEE802.11ay), and the EDMG-STF may include a training signal for the second legacy station.

Here, control information fields (L-STF, L-CEF, L-header, EDMG header A, EDMG-STF, EDMG-CEF, and EDMG-header B) of the physical layer, which are added to the front end of the data, may be collectively called a preamble. Further, a portion including the L-STF, L-CEF, and L-header fields may be referred to as a non-EDMG portion, and the remaining portion may be referred to as an EDMG portion. In addition, the L-STF, L-CEF, L-Header, and EDMG-Header-A fields may be called pre-EDMG modulated fields, and the remaining portions may be called EDMG modulated fields.

Meanwhile, the PPDU frame structure shown in FIG. 12 a is merely an example and may be provided in a different form, for example, as shown in FIG. 12 b . FIG. 12 b is a structure in which the EDMG-header B is omitted.

FIG. 13 a and FIG. 13 b are PPDU frames of the physical layer to which the MPDU frame may be mapped according to another example. These are A-PPDU frames.

Referring to FIG. 13 a , when the A-PPDU frame is represented as a logical bit level, it may include L-STF, L-CEF, L-header (legacy-header), EDMG-header A, EDMG-STF, EDMG-STF, PSDU1, EDMG-header A, PSDU2, and TRN. These fields may be optionally included according to PPDU type (e.g., SU PPDU, MU PPDU, etc.). The L-STF includes a training signal. The L-header may include control information for a first legacy station (e.g., a station supporting IEEE802.11ad), the EDMG-header may include control information for a second legacy station (e.g., a station supporting IEEE802.11ay), and the EDMG-STF may include a training signal for the second legacy station.

Referring to FIG. 13 b , each field of the A-PPDU frame may be transmitted during the illustrated time interval. The L-header includes L-header block 1 and L-header block 2, and the EDMG-header A includes EDMG-header A1 and EDMG-header A2.

FIG. 14 is an example in which an MPDU frame is mapped to a PPDU frame. Specifically, FIG. 14 shows that the MPDU frame shown in FIG. 5 is mapped to the PPDU frame shown in FIG. 12 a.

Referring to FIG. 14 , the second candidate MPDU frame may be all carried on (i.e., mapped to) the data region of a PPDU as a PSDU. That is, the MPDU frame of FIG. 8 and the first to fourth candidate MPDU frames may be mapped to the PPDU frame as well as the MPDU frame of FIG. 5 . FIG. 14 is merely an example, and the PPDU frame to which the MPDU frame is mapped may have the same form as FIG. 12B in which the EDMG-header B is omitted.

FIG. 15 is an example in which an MPDU frame is mapped to an A-PPDU frame. Specifically, FIG. 15 shows that the MPDU frame shown in FIG. 5 is mapped to the A-PPDU frame shown in FIG. 13 a.

Referring to FIG. 15 , the MAC header and the frame body of the MPDU frame may be carried on (i.e., mapped to) different or separate data regions. For example, the MAC header of the MPDU frame may be carried on (i.e., mapped to) PSDU1 and the frame body of the MPDU frame may be carried on (i.e., mapped to) PSDU2. That is, the MPDU frame of FIG. 8 and the first to fourth candidate MPDU frames may be mapped to the A-PPDU frame as well as the MPDU frame of FIG. 5 .

FIG. 16 is another example in which an MPDU frame is mapped to an A-PPDU frame. FIG. 16 is a case in which the second candidate MPDU frame (A-MSDU) according to FIG. 7 is mapped to the A-PPDU frame according to FIG. 13A. Hereinafter, a combination in which the second candidate MPDU frame is mapped to the A-PPDU frame is referred to as a sixth candidate (Candi.6) combination for convenience.

Referring to FIG. 16 , in the sixth candidate combination, the MAC header and the frame body of the second candidate MPDU frame are allocated to different PSDUs and mapped to data regions at different positions within the A-PPDU frame.

As an example, the MAC layer of the transmitting side transmits the second candidate MPDU frame to the physical layer of the transmitting side, and the physical layer of the transmitting side separates the second candidate MPDU frame into a MAC header and a frame body, and then maps the MAC header to PSDU 1 and maps the frame body to PDSU 2. Thereafter, the physical layer of the transmitting side generates an A-PPDU including a preamble, PSDU 1, and PSDU 2 and transmits the generated A-PPDU to the receiving side. Upon reception of the A-PPDU, the physical layer of the receiving side extracts the MAC header from PSDU 1, extracts the frame body from PSDU 2, and forwards a second candidate MPDU frame in which the extracted MAC header and frame body are combined to the MAC layer of the receiving side. Then, the MAC layer of the receiving side interprets and reads the second candidate MPDU frame based on the control information fields of the MAC header, and then decodes data of the frame body.

The performance of the sixth candidate combination according to FIG. 16 is as shown in FIG. 17 .

FIG. 17 is another example of results of simulation for comparing the performances of various MPDU frames.

Referring to FIG. 17 , TRX time of the MPDU frames of (a), (d), and (c) of FIG. 4 which correspond to the legacy MPDU frame is compared with TRX time of the second candidate MPDU frame and the sixth candidate combination (upper table) and compared with MAC dummy (lower table).

Since the sixth candidate combination is an A-PPDU frame structure, it includes PSDU 1 and EDMG-header B. PSDU 1 and EDMG-header B are a dummy of the physical layer added when the A-PPDU frame is used and occupy a transmission time of 1,160 ns as shown in FIG. 13 b . From the viewpoint of reducing the MAC dummy, the sixth candidate combination has the best performance, but the sixth candidate combination requires an additional transmission time of 1,160 ns due to the dummy of the physical layer. Meanwhile, since the sixth candidate combination does not include the MAC header for PSDU 2, backward compatibility for legacy stations may not be guaranteed. Hereinafter, an MPDU frame configured to include the MAC header per PSDU such that legacy stations can recognize and interpret a PSDU of each data region when the MPDU frame is separated and mapped to a plurality of data regions of the A-PPDU frame is disclosed.

FIG. 18 is another example in which an MPDU frame is mapped to an A-PPDU frame. FIG. 18 is a case in which an MPDU frame similar to the third candidate MPDU frame (A-MSDU) (hereinafter referred to as a third' candidate MPDU frame) is mapped to the A-PPDU frame according to FIG. 13 a.

Referring to FIG. 18 , the third' candidate MPDU frame includes a MAC header, a frame body, and an FCS.

Specifically, the MAC header of the third' candidate MPDU frame includes an FC field, a duration field, an RA field, a TA field, a BSSID field, a length field, a QoS field and an FCS field regarding the MAC header sequentially from the left where the MAC header starts to the right.

Meanwhile, the frame body includes a header of the frame body and a plurality of sub-bodies. Here, the header of the frame body may include at least some (e.g., the FC field, the duration field, the RA field, the TA field, the BSSID field, the length field, and the QoS field) of the control information fields of the MAC header of the MPDU frame.

Each sub-body includes a sequence field, an MSDU, and an FCS regarding the MSDU (or sub-body) sequentially from the left, where the sub-body starts, to the right.

The third' candidate MPDU frame is different from the third candidate MPDU frame in that it further includes the MAC header (the FC field, the duration field, the RA field, the TA field, the BSSID field, the length field, and the QoS field) at the front end of sub-body 1, and the remaining portion is the same as that of the third candidate MPDU frame.

Hereinafter, a combination in which the third' candidate MPDU frame is mapped to the A-PPDU frame is called a seventh candidate (Candi.7) combination for convenience.

In the seventh candidate combination, the MAC header and the frame body of the third' candidate MPDU frame are allocated to different PSDUs and are mapped to data regions at different positions within the A-PPDU frame. In this case, PSDUs need to be extracted from a plurality of data regions in the A-PPDU frame, and thus a MAC header is required for each PSDU such that legacy stations can recognize and interpret the PSDU of each of the data regions. From this point of view, the seventh candidate combination includes a MAC header corresponding to each PSDU, and this MAC header includes at least up to the RA field, thereby guaranteeing backward compatibility with legacy stations. That is, the seventh candidate combination has an advantage of providing backward compatibility compared to the sixth candidate combination.

The MAC layer of the transmitting side transmits the third' candidate MPDU frame to the physical layer of the transmitting side, and the physical layer of the transmitting side separates the third' candidate MPDU frame into the MAC header and the frame body, maps the MAC header to PSDU 1, and maps the frame body to PDSU 2. Thereafter, the physical layer of the transmitting side generates an A-PPDU including a preamble, PSDU 1 and PSDU 2 and transmits the generated A-PPDU to the receiving side.

Upon reception of the A-PPDU frame, the physical layer of the receiving side interprets the A-PPDU frame based on the preamble of the A-PPDU frame, and extracts and decodes a data region based on the preamble of the A-PPDU frame to obtain PSDU 1 and PSDU 2. Next, the physical layer of the receiving side extracts the MAC header from PSDU 1, extracts the frame body and the FCS from PSDU 2, and forwards a seventh candidate MPDU frame in which the MAC header, the frame body and the FCS are combined to the MAC layer. The MAC layer interprets the seventh candidate MPDU frame based on the MAC header and the header of the frame body. Specifically, the MAC layer sequentially decodes the FC field, the duration field, and the RA field included in the MAC header and checks whether the corresponding MPDU frame is an MPDU frame intended therefor from the RA field. When the address indicated by the RA field is the same as the address of the receiving side, it can be confirmed that the corresponding MPDU frame is an MPDU frame intended for the receiving side. If it is confirmed that the MPDU frame is intended for the receiving side in this manner, the MSDU of each sub-body is obtained based on the length field and the QoS field. The MAC layer of the receiving side checks whether there is an error in transmission of the MSDU based on the FCS regarding each MSDU, and if it is determined that there is no transmission error, forwards the corresponding MSDU to the higher layer.

FIG. 19 is another example in which an MPDU frame is mapped to an A-PPDU frame.

Referring to FIG. 19 , an eighth candidate (Candi.8) MPDU frame is an MPDU frame in which elements that are not essential in the wireless AV system are omitted from the MAC header and is designed to satisfy backward compatibility with legacy stations. That is, fields up to the first address information field of the MAC header are not changed and fields subsequent to the first address information field may be omitted such that the MAC header is reduced. Accordingly, backward compatibility with IEEE 802.11ad or ay standards can be maintained.

This eighth candidate MPDU frame includes a MAC header, a frame body, and an FCS.

Specifically, the MAC header of the eighth candidate MPDU frame includes an FC field, a duration field, an RA field, a length field, a QoS field, and an FCS field regarding the MAC header sequentially from the left where the MAC header starts to the right. Meanwhile, the frame body includes a header of the frame body and a plurality of sub-bodies. Here, the header of the frame body may include at least some (e.g., the FC field, the duration field, and the RA field) of the control information fields of the MAC header of the MPDU frame.

Each sub-body includes a sequence field, an MSDU, and an FCS regarding an MSDU (or a sub-body) sequentially from the left, where the sub-body starts, to the right.

The MAC layer of the transmitting side generates the eighth candidate MPDU frame and transmits the same to the physical layer of the transmitting side, and the physical layer of the transmitting side maps the eighth candidate MPDU frame as a PSDU to the A-PPDU frame. At this time, the physical layer of the transmitting side separates the eighth candidate MPDU frame into the MAC header, the frame body, and the FCS, maps the MAC header to PSDU 1, and maps the frame body and the FCS to PDSU 2. Next, the physical layer of the transmission side adds a preamble (i.e., L-STF, L-CEF, L-header, EDMG-header A, EDMG-STF, and EDMG-CEF) to the front end of PSDU 1, adds EDMG-header B to the rear end of PSDU 1, and adds PSDU 2 and TRN after EDMG-header B to generate an A-PPDU frame. The physical layer of the transmitting side transmits the generated A-PPDU frame to the receiving side.

Upon reception of the A-PPDU frame, the physical layer of the receiving side interprets the A-PPDU frame based on the preamble of the A-PPDU frame, and extracts and decodes a data region based on the preamble of the A-PPDU frame to obtain PSDU 1 and PSDU 2. Next, the physical layer of the receiving side extracts the MAC header from PSDU 1, extracts the frame body and the FCS from PSDU 2, and forwards the eighth candidate MPDU frame in which the MAC header, the frame body, and the FCS are combined to the MAC layer. The MAC layer interprets the eighth candidate MPDU frame based on the MAC header and the header of the frame body. Specifically, the MAC layer sequentially decodes the FC field, the duration field, and the RA field included in the MAC header and checks whether the corresponding MPDU frame is an MPDU frame intended for the receiving side from the RA field. When the address indicated by the RA field is the same as the address of the receiving address, it can be confirmed that the corresponding MPDU frame is an MPDU frame intended for the receiving side. If it is confirmed that the MPDU frame is intended for the receiving in this manner, the MSDU of each sub-body is obtained based on the length field and the QoS field. The MAC layer of the receiving side checks whether there is an error in transmission of the MSDU based on the FCS regarding each MSDU, and if it is determined that there is no transmission error, forwards the corresponding MSDU to the higher layer.

In the embodiment with respect to FIG. 19 , when the transmitting side is the wireless data transmission apparatus 1100 and the receiving side is the wireless data reception apparatus 1200, the operations of the MAC layer and the physical layer of the transmitting side may be performed by the communication unit 1140 of the wireless data transmission apparatus 1100 and the operations of the MAC layer and the physical layer of the receiving side may be performed by the communication unit 1210 of the wireless data reception apparatus 1200. On the other hand, in the embodiment with respect to FIG. 19 , when the transmitting side is the wireless data reception apparatus 1200 and the receiving side is the wireless data transmission apparatus 1100, the operations of the MAC layer and the physical layer of the transmitting side may be performed by the communication unit 1210 of the wireless data reception apparatus 1200 and the operations of the MAC layer and the physical layer of the receiving side may be performed by the communication unit 1140 of the wireless data transmission apparatus 1100.

FIG. 20 is another example in which an MPDU frame is mapped to a PPDU frame. The PPDU frame exemplified here is the PPDU frame shown in FIG. 12 b . However, it goes without saying that the PPDU frame according to FIG. 12 a may also be used.

Referring to FIG. 20 , a ninth candidate (Candi.9) MPDU frame is an MPDU frame in which elements (e.g., the TA field and the BSSID field) that are not essential in the wireless AV system are omitted from the MAC header and is designed to satisfy backward compatibility with legacy stations. That is, fields up to the first address information field of the MAC header are not changed and fields subsequent to the first address information field may be omitted such that the MAC header is reduced. Accordingly, backward compatibility with IEEE 802.11ad or ay standards can be maintained.

The ninth candidate MPDU frame includes a MAC header, a frame body, and an FCS regarding the MAC header.

Specifically, the MAC header of the ninth candidate MPDU frame includes an FC field, a duration field, an RA field, a length field, a QoS field, and an FCS field regarding the MAC header sequentially from the left where the MAC header starts to the right. Meanwhile, the frame body includes a header of the frame body and a plurality of sub-bodies. Here, the header of the frame body may include at least some (e.g., the FC field, the duration field, and the RA field) of the control information fields of the MAC header of the MPDU frame.

Each sub-body includes a sequence field, an MSDU, and an FCS regarding the MSDU (or sub-body) sequentially from the left, where the sub-body starts, to the right.

The MAC layer of the transmitting side generates the ninth candidate MPDU frame and transmits the same to the physical layer of the transmitting side, and the physical layer of the transmitting side maps the ninth candidate MPDU frame as a PSDU to a PPDU frame. In this case, the physical layer of the transmitting side separates the ninth candidate MPDU frame into the MAC header, the frame body, and the FCS.

The physical layer of the transmitting side maps at least some control information fields of MAC header or the indication of the control information fields to a preamble and maps the frame body and the FCS to the data region as a PSDU. That is, at least some fields or indications of the MAC header are mapped to the preamble, and the frame body and the FCS are mapped to the data region.

As an example, the physical layer of the transmitting side may map at least one of the RA field, the length field, and the QoS field among the control information fields of the MAC header to the preamble. Here, the preamble to which at least one of the RA field, the length field, and the QoS field is mapped may be, for example, EDMG-header A.

Next, the physical layer of the transmission side adds preambles (i.e., L-STF, L-CEF, L-header, EDMG-header A, EDMG-STF, and EDMG-CEF) to the front end of the data region (PSDU) and adds a TRN to the rear end of the data region (PSDU) to generate a PPDU frame. Then, the physical layer of the transmitting side transmits the generated PPDU frame to the receiving side.

Upon reception of the PPDU frame, the physical layer of the receiving side interprets the PPDU frame based on the preamble of the PPDU frame. Specifically, the physical layer of the receiving side may obtain MAC header related information mapped to the preamble from the preamble of the PPDU frame. For example, the physical layer of the receiving side may obtain information related to at least one of the RA field, the length field, and the QoS field from EDMG-header A.

The physical layer of the receiving side extracts and decodes the data region based on analysis of the preamble of the PPDU frame to obtain the PSDU.

Next, the physical layer of the receiving side acquires the frame body and the FCS from the PSDU, generates a ninth candidate MPDU frame, and forwards the same to the MAC layer.

The MAC layer of the receiving side interprets the ninth candidate MPDU frame based on the MAC header and the header of the frame body. Specifically, the MAC layer checks whether the corresponding MPDU frame is an MPDU frame intended for the receiving side from the RA value. When the address indicated by the RA value is the same as the address of the receiving side, it can be confirmed that the corresponding MPDU frame is an MPDU frame intended for the receiving side. If it is confirmed that the MPDU frame is intended for the receiving side in this manner, the MSDU of each sub-body is obtained based on the length field and the QoS field. The MAC layer of the receiving side checks whether there is an error in transmission of the MSDU based on the FCS regarding each MSDU, and if it is determined that there is no transmission error, forwards the corresponding MSDU to the higher layer.

In the embodiment with respect to FIG. 20 , when the transmitting side is the wireless data transmission apparatus 1100 and the receiving side is the wireless data reception apparatus 1200, the operations of the MAC layer and the physical layer of the transmitting side may be performed by the communication unit 1140 of the wireless data transmission apparatus 1100 and the operations of the MAC layer and the physical layer of the receiving side may be performed by the communication unit 1210 of the wireless data reception apparatus 1200. On the other hand, in the embodiment with respect to FIG. 20 , when the transmitting side is the wireless data reception apparatus 1200 and the receiving side is the wireless data transmission apparatus 1100, the operations of the MAC layer and the physical layer of the transmitting side may be performed by the communication unit 1210 of the wireless data reception apparatus 1200 and the operations of the MAC layer and the physical layer of the receiving side may be performed by the communication unit 1140 of the wireless data transmission apparatus 1100.

Hereinafter, a specific method of mapping at least some control information fields of the MAC header to a preamble of a PPDU according to FIG. 20 is disclosed.

According to an embodiment, the remaining fields except for some of the control information fields of the MAC header may be mapped to the preamble of the PPDU. That is, not all control information fields of the MAC header are mapped to the preamble of the PPDU. This is for the purpose of reducing MAC overhead. A control information field of the MAC header, which is removed before the transmitting side (or the physical layer of the transmitting side, the MAC layer of the transmitting side, or PLCP of the transmitting side, hereinafter referred to as the receiving side for convenience) maps the MAC header to the preamble of the PPDU, is called a removed field, and a control information field of the MAC header, which is not removed, is called a remaining field.

As an example, the remaining field may include the RA field, the length field, and the QoS field, and the removed field may include the FC field, the duration field, and the FCS. If this is described as an operation of the transmitting side, the transmitting side may map at least one of the RA field, the length field, and the QoS field to the preamble of the PPDU (or A-PPDU).

Since removed fields are only generated in the process of performing a regular operation of the MAC layer and are not transmitted to the receiving side, MAC overhead of 8 bytes can be reduced. At this time, the receiving side (or the physical layer of the receiving side, the MAC layer of the receiving side, or PLCP of the receiving side, hereinafter referred to as the receiving side for convenience) may perform an additional procedure of restoring removed fields that are not transmitted from the transmitting side or ignore the removed fields without performing the additional procedure.

The preamble of the PPDU includes L-STF, L-CEF, L-header, and EDMG-header A. Here, the preamble of the PPDU to which the remaining field is mapped may be, for example, EDMG-header A. That is, the preamble to which at least one of the RA field, the length field, and the QoS field is mapped may be EDMG-header A. The transmitting side may map the remaining field (at least one of the RA field, the length field, and the QoS field) to the EDMG-header A.

Hereinafter, a method of mapping a remaining field to EDMG-header A is disclosed.

The control information included in EDMG-header A is shown in Table 3, for example.

TABLE 3 Fields Bits Reserved Bits SU/MU Format 1 0 Channel Aggregation 1 0 BW 8 0 Primary Channel Number 3 0 Beamformed 1 0 Short/Long LDPC 1 0 STPC Applied 1 0 PSDU Length 22 0 Number of SS (spatial stream) 3 0 MCS Base MCS 5 0 Differential EDMG-MCS1 2 0 Differential EDMG-MCS2 2 0 Reserved 12 12 DCM BPSK Applied 1 0 NUC Applied 1 0 EDMG TRN Length 8 0 RX TRN-Units per Each Tx TRN-Unit 8 0 EDMG TRN-Unit P 2 0 EDMG TRN-Unit M 4 0 EDMG TRN-Unit N 2 0 TRN Subfield Sequence Length 2 0 TRN-Unit RX Pattern 1 0 EDMG Beam Tracking Request 1 0 EDMG Beam Tracking Request Type 1 0 Phase Hopping 1 0 Open Loop Precoding 1 0 Additional EDMG PPDU 1 0 Superimposed Code Applied 1 0 π/2-8-PSK Applied 1 0 Number of Transmit Chains 3 0 DMG TRN 1 0 Tone Pairing Type 1 0 Reserved 9 0 CRC 16 0

Referring to Table 3, the control information fields in EDMG-header A may be optionally included according to PPDU type (e.g., SU PPDU, MU PPDU, etc.). A total of 21 bits are allocated to the MCS field, in which 5 bits are allocated for the base MCS and 2 bits are allocated for each differential EDMG-MCS n. Since the number of spatial streams (SS) is 3, EDMG-header A includes only the base MCS, differential EDMG-MCS1, and differential EDMG-MCS2, and 5+2+2=9 bits are allocated thereto. In this case, only 9 bits out of the total of 21 bits allocated to the MCS field are used for actual MCS indication, and the remaining 12 bits for differential EDMG-MCS3 to 8 are reserved bits.

Meanwhile, the sum of the RA field, the length field, and the QoS field corresponding to the remaining fields is 10 bytes in total. For example, if EDMG-header A is 14 bytes, theoretically, all remaining fields of a total of 10 bytes can be mapped to EDMG-header A. In this case, the remaining fields may be inserted instead of some control information fields that originally constitute EDMG-header A. That is, bits (or bytes) allocated to a specific control information field of EDMG-header A may be allocated to the remaining fields. However, it is not desirable to remove some control information fields from Table 3 because EDMG-header A includes essential information required for restoration or communication of the corresponding PPDU frame.

Therefore, it is necessary to prepare some bits available for remaining field transmission in EDMG-header A and, if the bits are insufficient, to reduce or compress the remaining fields.

As an example, reserved allocable bits in EDMG-header A may be allocated for remaining field transmission. That is, the transmitting side may generate EDMG-header A by mapping remaining fields to the reserved bits of EDMG-header A. In this manner, EDMG-header A to which the remaining fields are mapped may be referred to as a modified EDMG-header A. In the case of Table 3, since the reserved bits in the MCS field determined by the number of SSs are 12 bits and common reserved bits in EDMG-header A are 9 bits, a total number of reserved bits is 21 bits. On the other hand, since the remaining fields are a total of 10 bytes (80 bits), the size of the remaining fields is too large to be transmitted by mapping the remaining fields to the reserved bits of EDMG-header A as they are.

Therefore, before mapping the remaining fields to EDMG-header A, the transmitting side may process, summarize, or simplify parameters (or content) indicated by the remaining fields and map the summarized remaining field parameters to EDMG-header A. For this, a method of summarizing indication of the remaining fields is required. Since the parameters indicated by the remaining fields are related to the wireless AV system, summarized parameters may be referred to as wireless AV frame parameters or a wireless AV frame table.

Wireless AV frame parameters according to an example may be defined as shown in Table 4. This considers a case in which all reserved bits (21 bits) in EDMG-header A are used (or allocated) for transmission of the remaining fields.

TABLE 4 Fields Bits Note Wireless AV data indication 1 0: legacy frame type 1: wireless AV data frame type Modified RA (AID) 16 16-bit AID acquired from association procedure Length index 2 Index with respect to each aggregated A-MSDU size table RDG 1 Used for reverse direction grant and additional PPDU indication Wireless AV tracking type 1 0: fast adaptation 1: nearby sector tracking

Referring to Table 4, wireless AV frame parameters may include at least some of a wireless AV data indication field, a modified RA field, a length index field, an RDG field, and a wireless AV tracking type field.

The wireless AV data indication field is, for example, 1 bit and indicates whether the corresponding PPDU frame or MPDU frame is a legacy frame type or a wireless AV data frame type according to the present disclosure. The modified RA field is, for example, 16 bits and may indicate a 16-bit AID (association ID) obtained from an association procedure. The length index field is, for example, 2 bits and may indicate an index with respect to an aggregated A-MSDU size table. The RDG field is, for example, 1 bit and may be used to indicate whether the corresponding PPDU frame is used for reverse direction grant or additional PPDU indication. The wireless AV tracking type is, for example, 1 bit and may indicate fast adaptation or nearby sector tracking as shown in FIG. 21 .

Based on the wireless AV frame parameters according to Table 4, 10-byte remaining fields may be mapped to or converted into 21-bit wireless AV frame parameters. That is, the transmitting side may generate 21-bit wireless AV frame parameters according to Table 4 based on the 10-byte remaining fields and generate a modified EDMG header A including the wireless AV frame parameters.

The modified EDMG header A including the wireless AV frame parameters according to Table 4 is shown in Table 5, for example.

TABLE 5 Fields Bits SU/MU Format 1 Channel Aggregation 1 BW 8 Primary Channel Number 3 Beamformed 1 Short/Long LDPC 1 STPC Applied 1 PSDU Length 22 Number of SS 3 MCS Base MCS 5 Differential 2 EDMG-MCS1 Differential 2 EDMG-MCS2 Wireless AV frame Wireless AV 1 parameter part 1 data indication Modified RA 11 [10:0] DCM BPSK Applied 1 NUC Applied 1 EDMG TRN Length 8 RX TRN-Units per Each Tx TRN-Unit 8 EDMG TRN-Unit P 2 EDMG TRN-Unit M 4 EDMG TRN-Unit N 2 TRN Subfield Sequence Length 2 TRN-Unit RX Pattern 1 EDMG Beam Tracking Request 1 EDMG Beam Tracking Request Type 1 Phase Hopping 1 Open Loop Precoding 1 Additional EDMG PPDU 1 Superimposed Code Applied 1 π/2-8-PSK Applied 1 Number of Transmit Chains 3 DMG TRN 1 Tone Pairing Type 1 Wireless AV frame Modified RA 5 parameter part 2 [15:11] Length index 2 RDG 1 Wireless AV 1 tracking type CRC 16

Referring to Table 5, wireless AV frame parameter part 1 is allocated to reserved bits (12 bits) in the MCS field determined by the number of SSs, and wireless AV frame parameter part 2 is allocated to normal reserved bits (9 bits). That is, the wireless AV frame parameters are divided into part 1 and part 2 and allocated to reserved bits in the MCS field and normal reserved bits, respectively. Here, part 1 is composed of 12 bits to match the reserved bits (12 bits) in the MCS field and part 2 is composed of 9 bits to match the normal reserved bits (9 bits).

As an example, part 1 may be composed of a total of 12 bits including a 1-bit wireless AV data indication field and 11 bits in the modified RA field (a portion corresponding to a bit string [10:0] of the modified RA field). Part 2 may be composed of a total of 9 bits including 5 bits in the modified RA field (a portion corresponding to a bit string [15:11] of the modified RA field), a 2-bit length index field, a 1-bit RDG field, and a 1-bit wireless AV tracking type field.

Of course, the present disclosure may also provide a method of dividing wireless AV frame parameters into part 1 and part 2 and a method of respectively allocating (mapping) part 1 and part 2 to a first reserved bit region (reserved bits in the MCS field) and a second reserved bit region (normal reserved bits).

Meanwhile, a case in which all the second reserved bit region (normal reserved bits) need to be set to 0 may be present. This means that the second reserved bit region cannot be used for wireless AV frame parameters. Therefore, an embodiment in which only the first reserved bit region is used for transmission of wireless AV frame parameters may also be required.

Wireless AV frame parameters according to another example may be defined as shown in Table 6. This is an embodiment in which only the first reserved bit region in EDMG-header A is used for transmission of remaining fields (i.e., wireless AV frame parameters).

TABLE 6 Fields Bits Note Wireless AV 2 0: legacy frame type data indication 1: wireless AV data frame type, and length index length = 7920 bytes 2: wireless AV data frame type, length = xx bytes 3: wireless AV data frame type, length = yy bytes Modified RA 8 8-bit AID acquired from association (AID) procedure RDG 1 Used for reverse direction grant and additional PPDU indication Wireless AV 1 0: fast adaptation tracking type 1: nearby sector tracking

Referring to Table 6, the wireless AV frame parameters may include at least some of a wireless AV data indication and length index field, a modified RA field, an RDG field, and a wireless AV tracking type field. Table 6 is different from the wireless AV frame parameters according to Table 4 in that the wireless AV data indication field and the length index field are merged to become 2 bits, and the modified RA field is 8 bits.

Specifically, the wireless AV data indication and length index field is, for example, 2 bits and may indicate a total of 4 cases (indicate whether the corresponding PPDU frame or MPDU frame is a legacy frame type or a wireless AV data frame type according to the present disclosure and, at the same time, indicate whether the A-MSDU size is 7920 bytes, xx bytes, or yy bytes).

The modified RA field is, for example, 8 bits and may indicate an 8-bit association ID (AID) obtained from an association procedure. Basically, an EDMG station allocates an AID field value within a range of 1 to 254. At this time, an AID value of 255 is reserved as a broadcast AID and an AID value of 0 corresponds to an AP or a PCP. 8 MSBs of the AID field are reserved bits. The modified RA field according to Table 4 is 16 bits, whereas the modified RA field according to Table 6 is 8 bits.

The RDG field is, for example, 1 bit and may be used for reverse direction grant and additional PPDU indication. The wireless AV tracking type is, for example, 1 bit and may indicate fast adaptation or nearby sector tracking as shown in FIG. 21 .

Based on the wireless AV frame parameters according to Table 6, 10-byte remaining fields may be mapped or converted into 12-bit wireless AV frame parameters. That is, the transmitting side may generate 21-bit wireless AV frame parameters according to Table 6 based on the 10-byte remaining fields and generate a modified EDMG header A including the wireless AV frame parameters.

The modified EDMG header A including the wireless AV frame parameters according to Table 6 is shown in Table 7, for example.

TABLE 7 Fields Bits SU/MU Format 1 Channel Aggregation 1 BW 8 Primary Channel Number 3 Beamformed 1 Short/Long LDPC 1 STPC Applied 1 PSDU Length 22 Number of SS 3 MCS Base MCS 5 Differential 2 EDMG-MCS1 Differential 2 EDMG-MCS2 Wireless AV frame Wireless AV data 2 parameter part 1 indication and length index Modified RA 8 (8 bit AID) RDG 1 Wireless AV 1 tracking type DCM BPSK Applied 1 NUC Applied 1 EDMG TRN Length 8 RX TRN-Units per Each Tx TRN-Unit 8 EDMG TRN-Unit P 2 EDMG TRN-Unit M 4 EDMG TRN-Unit N 2 TRN Subfield Sequence Length 2 TRN-Unit RX Pattern 1 EDMG Beam Tracking Request 1 EDMG Beam Tracking Request Type 1 Phase Hopping 1 Open Loop Precoding 1 Additional EDMG PPDU 1 Superimposed Code Applied 1 π/2-8-PSK Applied 1 Number of Transmit Chains 3 DMG TRN 1 Tone Pairing Type 1 Reserved 9 CRC 16

Referring to Table 7, the wireless AV frame parameters according to Table 6 are allocated to reserved bits (12 bits) in the MCS field determined by the number of SSs. That is, 2 bits are allocated to the wireless AV data indication and length index field, 8 bits are allocated to the modified RA field, 1 bit is allocated to the RDG field, and 1 bit is allocated to the wireless AV tracking type field.

FIG. 22 illustrates a wireless AV data frame including the modified EDMG header A according to an embodiment. In FIG. 22 , when a legacy station and the wireless data reception apparatus according to the present disclosure receive the wireless AV data frame (PPDU frame) according to FIG. 22 , operations of processing the wireless AV data frame are compared and described.

Referring to FIG. 22 , the legacy station may demodulate and decode all of the L-STF, L-CEF, and L-headers that are non-EDMG portions. For legacy station, the EDMG portion starting from the modified EDMG header A is only shown as a data region. Accordingly, the legacy station may demodulate and decode up to the FC field, the persistence field, and the RA field, which are identifiable data regions based on the modified EDMG-header A. In addition, the legacy station confirms that this PPDU frame is not intended therefor based on the RA field, does not handle the remaining portion after the RA field, performs an error check with the last FCS, and then terminates the demodulation and decoding operation.

On the other hand, the wireless data reception apparatus according to the present disclosure may acquire wireless AV frame parameters included in the modified EDMG header A. The modified EDMG header A may be, for example, as shown in Table 5 or Table 7, and the wireless AV frame parameters may be, for example, as shown in Table 4 or Table 6. That is, the wireless data reception apparatus may obtain at least some of the wireless AV data indication, the length index, the modified RA, RDG, and the wireless AV tracking type from the modified EDMG header A.

For example, the wireless data reception apparatus may confirm that this PPDU frame is a wireless AV data frame based on the wireless AV data indication. In addition, the wireless data reception apparatus may perform demodulation and decoding on the data region upon confirming that this PPDU frame is intended therefor based on the modified RA field.

The wireless data reception apparatus may demodulate and decode the PSDU in the PPDU frame to obtain a ninth candidate (Candi.9) MPDU frame or a part (PSDU2 part) thereof and read a plurality of sub-bodies included in the frame body. After demodulating and decoding the MSDU for each sub-body, the wireless data reception apparatus may check a block ACK error through the FCS for each sub-body and determine whether to perform retransmission for each sub-body (or for each MSDU). If it is determined that an error has been generated in reception of a specific sub-body (or a specific MSDU), the wireless data reception apparatus requests retransmission of the MSDU of the specific sub-body in which the error has been generated from a wireless data transmission apparatus.

FIG. 23 is another example of results of simulation for comparing the performances of various MPDU frames.

Referring to FIG. 23 , TRX time of the MPDU frames of (a), (d), and (c) of FIG. 4 which correspond to the legacy MPDU frame and TRX time of the second candidate MPDU frame, the sixth candidate combination, and the ninth candidate combination are compared (upper table) and compared to a MAC dummy (lower table).

Since the sixth candidate combination includes a dummy (PSDU 1 and EDMG-header A) of the physical layer added when the A-PPDU frame is used, it has a disadvantage of occupying a transmission time of 1,160 ns as shown in FIG. 13 b . On the other hand, in the ninth candidate combination, since the MPDU frame is mapped to a normal PPDU, a dummy of the physical layer is not separately added, and further, control information fields (TA field and BSSID field) unnecessary for the wireless AV system are removed, and thus the performance is excellent.

Since the device and method for receiving wireless data or the device and method for transmitting wireless data according to the above-described embodiments of the present disclosure do not mandatorily require all of the components or operations that are described above, the device and method for receiving wireless data or the device and method for transmitting wireless data may be performed by including all or part of the above-described components or operations. Additionally, the above-described embodiments of the device and method for receiving wireless data or the device and method for transmitting wireless data may be performed in combination with each other. Furthermore, the above-described components or operations are not mandatorily required to be performed in the order that is described above, and, therefore, it is also possible for components or operations (or process steps) that are described in a later order to be performed before the components or operations (or process steps) that are described in an earlier order.

The foregoing description has been presented merely to provide an exemplary description of the technical idea of the present disclosure, and it will be apparent to those skilled in the art to which the present disclosure pertains, that various changes and modifications in the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Therefore, the embodiments of the present disclosure described above can be implemented separately or in combination with each other.

The embodiments disclosed herein are provided not to limit the technical idea of the present disclosure but to describe the present disclosure, and the scope of the technical idea of the present disclosure should not be limited to these embodiments. The scope of the present disclosure should be interpreted by the following claims, and all technical ideas within the scope of equivalents thereto should be construed as being included in the scope of the present disclosure. 

What is claimed is:
 1. An apparatus for transmitting data in a wireless audio video (AV) system, the apparatus comprising: a processor configured to encode media data to generate a compressed bitstream; and a communication unit configured to: fragment the compressed bitstream, map the fragmented compressed bitstream to a medium access channel (MAC) service data unit (MSDU); generate a MAC protocol data unit (MPDU) sequentially including a MAC header, a frame body, and a frame check sequence (FCS) regarding the MAC header for transmission of the MSDU; generate a PHY protocol data unit (PPDU) sequentially including a preamble to which at least a part of the MAC header is mapped, at least one PHY service data unit (PSDU) to which the frame body and the FCS are mapped, and a training (TRN) field; and transmit the PPDU frame through a wireless channel, wherein the preamble to which the at least a part of the MAC header is mapped is an enhanced directional multi-gigabit-header A (EDMG-header A), wherein the EDMG-header A sequentially includes a frame control (FC) field, a duration field, a receiver address (RA) field, a length field, a quality of service (QoS) field and a frame check sequence (FCS) field, and does not include a transmitter address (TA) field and a basic service set identifier (BSSID) field, wherein the frame body includes a header and a plurality of sub-bodies, wherein the header of the frame body includes at least some control information of the MAC header of the MPDU, and wherein the plurality of sub-bodies sequentially includes a sequence field, the MSDU, and an FCS regarding the MSDU.
 2. The apparatus of claim 1, wherein 0 bit is allocated to a service set ID (SSID) field in the MAC header.
 3. The apparatus of claim 1, wherein the communication unit is further configured to generate wireless AV frame parameters based on at least one of the RA field, the length field or the QoS field and map the wireless AV frame parameters to the EDMG header A in the preamble.
 4. The apparatus of claim 3, wherein the wireless AV frame parameters include at least one of a field indicating whether the PPDU frame 1 s a wireless AV data frame, a modified RA field based on an association ID (AID), an index field with respect to an A-MSDU size or a field indicating whether the PPDU frame is used for reverse direction grant, and a field indicating a wireless AV tracking type.
 5. The apparatus of claim 3, wherein the communication unit is further configured to map the wireless AV frame parameters to at least some bits of an MCS field in the EDMG header A.
 6. The apparatus of claim 5, wherein a number of the at least some bits of the MCS field is determined by a number of spatial streams.
 7. The apparatus of claim 5, wherein the communication unit is further configured to determine whether to perform retransmission in units of an MSDU of each sub-body based on an FCS regarding the frame body.
 8. An apparatus for receiving data in a wireless audio video (AV) system, the apparatus comprising: a communication unit configured to: receive a PHY protocol data unit (PPDU) frame through a wireless channel; obtain a preamble, at least one PHY service data unit (PSDU), and a training (TRN) field from the PPDU frame: obtain wireless AV frame parameters from at least a part of the preamble; obtain a MAC protocol data unit (MPDU) frame from the PSDU; obtain a MAC header, a frame body, and a frame check sequence (FCS) regarding the MAC header from the MPDU frame: obtain a fragmented medium access channel (MAC) service data unit (MSDU) from the frame body; and obtain a compressed bitstream from the fragmented MSDU; and a processor configured to decode the compressed bitstream to obtain media data, wherein the preamble to which at least a part of the MAC header is mapped is an enhanced directional multi-gigabit-header A (EDMG-header A), wherein the EDMG-header A sequentially includes a frame control (FC) field, a duration field, a receiver address (RA) field, a length field, a quality of service (QoS) field and a frame check sequence (FCS) field, and does not include a transmitter address (TA) field and a basic service set identifier (BSSID) field, wherein the frame body includes a header and a plurality of sub-bodies, wherein the header of the frame body includes at least some control information of the MAC header of the MPDU frame, and wherein the plurality of sub-bodies sequentially includes a sequence field, the MSDU, and an FCS regarding the MSDU.
 9. The apparatus of claim 8, wherein 0 bit is allocated to a service set ID (SSID) field in the MAC header.
 10. The apparatus of claim 8, wherein the wireless AV frame parameters include at least one of a field indicating whether the PPDU frame 1 s a wireless AV data frame, a modified RA field based on an association ID (AID), an index field with respect to an A-MSDU size, size or a field indicating whether the PPDU frame is used for reverse direction grant, and a field indicating a wireless AV tracking type.
 11. The apparatus of claim 8, wherein the wireless AV frame parameters are mapped to at least some bits of an MCS field in the EDMG header A.
 12. The apparatus of claim 11, wherein a number of the at least some bits of the MCS field is determined by a number of spatial streams.
 13. The apparatus of claim 8, wherein the communication unit is further configured to determine whether to perform retransmission in units of an MSDU of each sub-body based on an FCS regarding the frame body.
 14. The apparatus of claim 1, wherein the header of the frame body includes only an FC field, a duration field, and an RA field.
 15. The apparatus of claim 8, wherein the header of the frame body includes only an FC field, a duration field, and an RA field. 